Signing a zero-hours contract can mean a blank wage cheque at the end of the week. It has gained an ugly reputation because the contract says that instead of working a specific number of hours per week, workers must be ready to work whenever they are asked. There is no employment relationship.

Citizens Advice points out that similar "key time" contracts are also prevalent. They guarantee some work, but not regular hours each week.

If a worker is made to wait or take breaks on work premises, they must be paid, but if they wait at home for a call to come to work, only the hours on the job qualify for payment. The national minimum wage applies, but an employer is not obliged to offer sick leave or holiday pay, though a court may decide that consistent employment overrides these contract terms.

In some industries, workers on zero-hours contracts will agree to work according to weekly or monthly rotas. In other sectors, especially retail, workers may be called and told to come to work at a few hours' notice.